Erythrocyte protoporphyrin during recovery from undernutrition in rats.

Interrelationships between Erythrocyte Protoporphyrin (EP), dietary Iron/Pr otein ratio (Fe/Prot) and Fe liver content (Feh) were studied during nutrit ional recovery in an experimental model: weanling female Wistar rats (To) w ere depleted with a protein-free diet (LP), losing 20% of their initial bod y weight. Then they were recovered until 45 days of age (T45) with diets co ntaining: casein: 20 g/100g; Fe (ammonium Fe citrate) (ppm.): 0, 75 or 100 (groups A(1), A(2) and A(3), respectively). Hematocrit, Hemoglobin (Hb) (g/ dL), Erythrocyte Protoporphyrin (EP) (mu g/ dL Red Blood Cells) and Feh (mu g) were determined at To, LP and T45. Results were compared with control r ats (C) fed with 20% of casein and Fe, 50 ppm. EP: a) decreased in C from T o to T45 (99+/-24; 36+/-9; p < 0.01); b) increased in A(1) and A(2) at T45 (123+/-21; 93+/-29, respectively, p<0.01) while A(3) did not show significa nt difference (45+/-7) regarding to C; c) correlated inversely with Feh. Ac cording to the inverse correlation between EP and Fe/Prot (r = -0.99), we f ound that 92 ppm was an adequate Fe amount to prevent EP increase. These re sults confirm that during recovery from undernutrition EP depends on iron l iver content, being an adequate indicator of iron nutritional status; there fore, EP would be useful as a predictor of the optimum Fe/Prot ratio for nu tritional recovery.